<template>
  <view>
    <!-- 自定义搜索组件 -->
    <my-search @click="gotoSearch"></my-search>
    
    <view class="scroll-view-container">
      <!-- 左侧滑动区域 -->
      <scroll-view class="left-scroll-view" scroll-y :style="{height: wh + 'px'}">
        <block v-for="(item, id) in cateList" :key="id">
          <view :class="['left-scroll-item', activeIndex === id ? 'active' : '']" @click="activeChange(id)">{{item.cat_name}}</view>
        </block>
      </scroll-view>
      <!-- 右侧滑动区域 -->
      <scroll-view class="right-scroll-view" scroll-y :style="{height: wh + 'px'}" :scroll-top="Math.random()">
        <view class="right-scroll-item">
          <view class="cate-lv2" v-for="(item, i) in cateLevel2" :key="i">
            <!-- 二级分类 -->
            <view class="cate-lv2-title">/{{item.cat_name}}/</view>
            <!-- 三级分类 -->
            <view class="cate-lv3-list">
              <view class="cate-lv3-item" v-for="(item2, i2) in item.children" :key="i2" @click="gotoGoodsList(item2)">
                <image :src="item2.cat_icon"></image>
                <text>{{item2.cat_name}}</text>
              </view>
            </view>
          </view>
        </view>
      </scroll-view>
    </view>
  </view>
</template>

<script>
  import badge from '@/mixins/tabbar-badge.js'
	export default {
    mixins: [badgeMix],
		data() {
			return {
				wh: 0,
        // 一级分类数据
        cateList: [],
        // 控制选中项的样式
        activeIndex: 0,
        // 二级分类数据
        cateLevel2: []
			};
		},
    onLoad() {
      const sysInfo = uni.getSystemInfoSync()
      this.wh = sysInfo.windowHeight - 50
      this.getCateList()
    },
    methods: {
      async getCateList() {
        const { data: res } = await uni.$http.get('/api/public/v1/categories')
        if(res.meta.status !== 200) return uni.$showMsg()
        // 赋值前先把子节点赋值给二级分类数据
        this.cateLevel2 = res.message[0].children
        this.cateList = res.message
      },
      // 监听切换一级分类事件
      activeChange(i) {
        this.activeIndex = i
        // 当i变化时把对应的子节点数据重新赋值给二级分类
        this.cateLevel2 = this.cateList[i].children
      },
      // 点击三级分类跳转至商品列表页面
      gotoGoodsList(item2) {
        uni.navigateTo({
          url: "/subpkg/goods_list/goods_list?cid=" + item2.cat_id
        })
      },
      gotoSearch() {
        uni.navigateTo({
          url: "/subpkg/search/search"
        })
      }
    }
	}
</script>

<style lang="scss">
.scroll-view-container {
  display: flex;
  
  .left-scroll-view {
    width: 120px;
    
    .left-scroll-item {
      background-color: #f7f7f7;
      line-height: 60px;
      text-align: center;
      font-size: 12px;
      
      &.active {
        background-color: #ffffff;
        position: relative;
        
        &::before {
          content: ' ';
          display: block;
          width: 3px;
          height: 30px;
          background-color: #c00000;
          position: absolute;
          top: 50%;
          left: 0;
          transform: translateY(-50%);
        }
      }
    }
  }
}

.cate-lv2-title {
    font-size: 12px;
    font-weight: bold;
    text-align: center;
    padding: 15px 0;
  }
  
.cate-lv3-list {
  display: flex;
  flex-wrap: wrap;
  
  .cate-lv3-item {
    display: flex;
    width: 33.3%;
    flex-direction: column;
    align-items: center;
    margin-bottom: 10px;
    
    image {
      width: 60px;
      height: 60px;
    }
    
    text {
      font-size: 12px;
    }
  }
}
</style>
